Pantech's UML290 3G/4G/LTE USB modem has difficulty with the "hand-off" between the Verizon Wireless 3G network and 4G networks.  Users are finding that their modem works fine when locked to either 3G or 4G mode in a particular location, but when the modem is set to "auto" (i.e., when the modem is set to automatically connect to the fastest network available - 4G or 3G - this is the default setting on the modem), it has trouble making the switch between networks. This can result in difficulty making or maintaining connections in areas of marginal signal strength, modem "lock-ups" when the 4G service is temporarily interrupted, or other undesirable device behavior. Verizon has acknowledged that this is a problem and is working on a fix.

To lock the UML290 modem into either 3G or 4G modes, use the UML290 Pref Mode Tool available from the link below.  Follow these instructions to change the modem's preferred network setting.

• Insert the UML290 into a Windows PC and wait for it to be recognized by Windows
• Launch the UML290PMTool_v1.0.0.2.exe program
• Click the READ button to retrieve the current modem settings
• Select the appropriate options as shown in the figures below

Figure 1: UML290 Locked to 3G Mode

Figure 2: UML290 Locked to 4G (LTE) Mode

Figure 3: UML290 in Automatic 3G/4G Mode

• Click the WRITE button to save the new settings to the modem.  Do not remove the modem until the update process completes and the READ button becomes active again.
• Close the UML290PMTool program
• Remove the UML290 from your PC

You may now insert the UML290 into your router and it will operate in the selected 3G or 4G mode.  The router configuration is the same for 3G or 4G operation - no router configuration changes should be necessary in most instances. To change the UML290's operating mode in the future, run the UML290PMTool program again and select the desired settings.

NOTE: Do not use the "Diagnostic Settings" menu in the VZAccessManager software to change the UML290's operating mode. That technique does not set all of the necessary modem parameters for 3G-only operation.